1. Field of the Invention
This invention relates generally to igniters for gaseous fuel, and more particularly to igniters that include igniter elements and shields for protecting the igniter elements.
2. Background
Ceramic materials have enjoyed great success as igniters in e.g. gas-fired furnaces, stoves and clothes dryers. Ceramic igniter production includes constructing an electrical circuit through a ceramic component a portion of which is highly resistive and rises in temperature when electrified by a wire lead. See, for instance, U.S. Pat. Nos. 6,582,629; 6,278,087; 6,028,292; 5,801,361; 5,786,565; 5,405,237; and 5,191,508. See also U.S. Patent Publication 2003/0080193.
Typical igniters have been generally rectangular-shaped elements with a highly resistive “hot zone” at the igniter tip with one or more conductive “cold zones” providing to the hot zone from the opposing igniter end. One currently available igniter, the Mini-Igniter™, available from Norton Igniter Products of Milford, N.H., is designed for 12 volt through 120 volt applications and has a composition comprising aluminum nitride (“AlN”), molybdenum disilicide (“MoSi2”), and silicon carbide (“SiC”).
Certain shield elements have been employed for ceramic igniters to provide enhanced mechanical integrity to the igniter system. See U.S. Pat. No. 6,777,650 to Hamel et al., which discloses highly useful igniter/shield systems.
Nevertheless, end-user demands require continued efforts to produce more robust igniter systems with greater manufacturing efficiencies.
It would therefore be desirable to have an igniter including an igniter element and a shield for protecting the igniter element from accidental or other unintended damage or breakage. It would be further desirable to have such an igniter system that is relatively inexpensive to manufactured use.